Golf swing analysis apparatus and method

ABSTRACT

A method and integrated golf club apparatus for directly measuring physical parameters of the golf club head motional acceleration swing forces, golf club head face, golf ball impact forces, and subsequent calculations of other metrics useful to a golfer&#39;s understanding of the effectiveness of his or her golf swing and impact result in totality. The physical parameters that are directly measured include three dimensional motion force vectors of club head prior to, during and after impact and full impact pressure force profiles across the golf clubface with respect to time. The force measurements are made by at least one piezoelectric or differential capacitance based acceleration g-force sensor internal to the club head and pressure impact force sensors integrated into the clubface. The sensors are connected to electronics which condition, record and store the time varying sensors information electronically, then process and translate the information into one of several forms for delivery to a human interface function.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.14/729,043, filed on Jun. 2, 2015 and entitled “Golf Swing AnalysisApparatus and Method,” which is a continuation of U.S. application Ser.No. 12/287,303, filed on Oct. 9, 2008 and entitled “Golf Swing AnalysisApparatus and Method,” each of which is incorporated by reference hereinin its entirety.

FIELD OF THE INVENTION

The present invention relates to a method for determining theeffectiveness of a golfer's swing and the associated golf club head timevarying force metrics before, during and after impact between a golfclub head and a golf ball. More specifically, the present inventionrelates to an integrated golf club capable of autonomous directmeasurement and information storage of three dimensional motionalacceleration forces of the club head during the swing, and complete clubhead and ball impact time varying force profiles across the entire clubhead face.

BACKGROUND OF THE INVENTION

For several decades, external systems separate from a golf club, orattaching sensors to a golf club, have been used to gather and inferinformation about the effectiveness of a golfer's swing. One of the mostcommon external systems relates to using high speed cameras to determinemetrics about a golfer's swing. Some of these systems estimate club headspeed and ball speed and spin after the ball leaves the club. However,the true forces introduced in the clubface and the club/ball impactinformation are estimates based upon indirect calculations of forceinferred from optical images.

The approach of using prior art golf club attachments can identify to anunacceptable approximate degree the impact area on the clubface.However, the precise location cannot be achieved because of theremovable nature of the sensors and the lack of relationship of timevarying force profiles of each sensor which is needed for a full energyimpact analysis.

An example of such an external system is U.S. Pat. No. 4,136,387 toSullivan et al., for a Golf Club Impact And Golf Ball LaunchingMonitoring System. Sullivan discloses a system that uses externalelectro-optical sensors to measure the location of a plurality of spotson the surface of the golf club head or the golf ball, each at twopoints in time. For the golf club head measurement the two points intime are just before ball impact; for the two points in time for thegolf ball, it is after impact. This device does not offer an integratedgolf club and does not allow for direct force measurements of the timevarying spatial and force profiles across the clubface and club headaccelerations' forces for accurate force dynamics associated with theclub swing and clubface/ball impact.

Another example of an external system is the Patent ApplicationPublication U.S. 2008/0020867 A1 to Manwaring for a method ofdetermining a golfer's golf club head orientation and impact locationfor a golf swing. The system uses an optical CMOS imaging system tomeasure angular velocity of the golf club, linear velocity of the golfclub, and ball launch properties. Then, through iterative calculationsusing the mass of the golf club and the ball, the device makesdeterminations as to club head orientation and clubface impact. Thispublication does not offer an integrated golf club and does not allowfor direct force measurements of the time varying spatial and forceprofiles across the clubface and club head accelerations' forces foraccurate force dynamics associated with the club swing and clubface/ballimpact.

Another example of an external system is shown in U.S. Pat. No.7,329,193 B2 to Plank, Jr. who claims a portable golf swing analyzingsystem separate from the golf club based on infrared sensors andultrasonic sensors. This publication does not offer an integrated golfclub and does not allow for direct force measurements of the timevarying spatial and force profiles across the clubface and club headaccelerations' forces for accurate force dynamics associated with theclub swing and clubface/ball impact.

An example of attaching sensors to a golf club is shown in U.S. Pat. No.4,898,389 to Plutt, who claims a self contained device for indicatingthe area of impact on the face of the club and the ball, and a means foran attachable and detachable sensor or sensor array that overlies theface of the club. Plutt's device does not provide for an imbedded impactsensor array in the clubface that functions in conjunction with internalthree dimensional g-force sensors to provide a superset of time varyingspatial force impact contours of the clubface with club headacceleration force parameters that can be calibrated for highly accuratespatial and force measurement. Plutt's device is susceptible to locationinaccuracy due to the removable constraint of the sensors and issusceptible to sensor damage since the sensors come in direct contactwith the ball.

Another example of attaching sensors to a golf club is shown in U.S.Pat. No. 7,264,555 B2 to Lee et al. which claims a diagnostic golf clubsystem that utilizes a golf club with strain gauges or other swing loadmeasuring means attached to the golf club shaft to determine swingcharacteristics. This device does not utilize sensors embedded with inthe club head.

Another example of attaching sensors to a golf club is U.S. Pat. No.5,792,000 to Weber et al. which claims a swing analysis system thatanalyzes sensors placed on the shaft of the golf club. This device doesnot utilize sensors embedded within the club head.

The prior art disclosures all fail to offer a fully integrated golf clubcapable of autonomously making time varying direct force measurementswith regards to three dimensional motional forces of the club headbefore, during and after golf club head/ball impact, and making directtime varying force measurements across the clubface surface.Accordingly, none of the prior art aggregates all of these directmeasurements with respect to a single time line allowing a large numberof metrics to be calculated.

SUMMARY OF THE INVENTION

The present invention is an integrated golf club that measures directlyand stores time varying forces during the golf club swing in the timespan around the point of golf club head and ball impact. Two categoriesof time varying forces are being measured in real time simultaneouslywith different mechanisms.

The first category of measured forces includes three dimensionalmotional acceleration forces on the club head during the club swing froma point in time before the initial club/ball impact until a point intime after club head and ball separation has taken place. Therelationship between force and acceleration is

(t)=m_(ch)

(t) where

(t) is the time varying force vector, m_(ch) is the known mass of theclub head and

(t) is the time varying acceleration vector experienced by a givenacceleration force sensor. The three dimensional axial domain of theacceleration force vectors has its origin at the center of gravity andthe axial domain is orientated with one axis referenced normal to theclub head face. The mechanism used to measure this category of motionalforces is a three dimensional g-force acceleration sensor or sensors.

The second category of force measurements includes the impact pressureforces that occur across the golf club head face for the duration ofclubface and ball impact. This time varying pressure force is a scalarpressure profile normal to the clubface that is a result of the impactforce and location of the ball on the clubface. The relationship betweenpressure and force is P(t)=

_(normal-to-A)(t)A where P(t) is the time varying pressure experiencedby a given pressure force sensor,

_(normal-to-A) is the time varying vector component of the force vectorthat is normal to the surface of the pressure force sensor and also theclubface, and A is the surface area of a given pressure force sensor.The axial reference domain is the same for the g-force sensors describedabove. The mechanism to measure this category of pressure forces is anarray or pressure force sensors embedded in the clubface that aremeasuring time varying impact pressure forces across the clubface duringthe entire duration of club head face and ball impact.

Both categories of dynamic direct vector measurements are related with asingle time line and a single shared physical domain allowing a largenumber highly accurate golf club swing, club/ball impact and club headto ball orientation metrics to be realized. To achieve this aggregate ofdirect physical measurements, the golf club head has embedded within itat least one acceleration three dimensional g-force sensor and at leastone, but preferably a plurality of impact pressure force sensorsgeometrically distributed in the club head face. From the aggregaterelated measurements of these two measurement systems associated with asingle time line and a defined spatial relationship to each other and tothe club head physic al structure, the following metrics are eitherdirectly measured or directly calculated (If a metric calculationrequires an assumption, such as ball surface condition and hencefriction coefficient, its is stated as an estimate):

-   -   1. Time varying pressure or force profile across the golf        clubface;    -   2. Location of impact of clubface and ball on clubface;    -   3. Duration in time of club head face and ball impact;    -   4. Maximum pressure or force measured on clubface;    -   5. Total energy transferred from club to ball;    -   6. Time varying three dimensional motional acceleration and        associated force vectors on club head before during and after        club head face and ball impact;    -   7. Radial acceleration forces on club for estimation of club        head velocity;    -   8. Three dimensional deceleration force vectors of club head        during the club/ball impact;    -   9. Force vector components that are transferred to ball launch        and ball spin;    -   10. Estimated percent of total energy components transferred to        ball trajectory and ball spin;    -   11. Club head orientation with respect to ball from before club        head/ball impact, during ball impact and after impact;    -   12. Orientation of ball spin referenced to club head face;    -   13. Estimation of ball launch velocity;    -   14. Estimation of ball spin velocity;    -   15. Impact error offset on clubface which is a distance from        actual impact location to optimum impact location;    -   16. Club head orientation percentage error from optimum in        relation to club head/ball impact (This could be described as a        error for each of three vectors describing forces on club head        from ball) and;    -   17. Measure of torque and angular momentum of the club head as        caused by the event of club head/ball impact.

The sensors are connected to electrical analog and digital circuitry,also embedded in the club head, that condition the signals from thesensors, samples the signals from all sensors simultaneously, convertsto a digital format, attaches a time stamp to each group of simultaneoussensor measurements, and then stores the data in memory. The process ofsampling sensors simultaneously is sequentially repeated at a fast rateso that all forces' profile points from each sensor are relativelysmooth with respect to time. The minimum sampling rate is the “Nyquistrate” of the highest significant and pertinent frequency domaincomponent of the sensors' time wave for any of the sensors.

Thus, the present invention encompasses a variety of options for thegolfer to receive and interpret the information of swing, impact andorientation metrics or a subset of total metrics available. The humaninterface function can be either integrated into the club or a separatehuman interface module that the golf club communicates with eitherthrough wires or wirelessly. The human interface function can be all orany subset of audible, visual, temperature or vibration signals forhuman interpretation.

A further advantage of the present invention is that in its preferredembodiment, the integrated club communicates with an external humaninterface apparatus through a wireless connection. The wirelessconnection could be Bluetooth™, Zigbee™, Wifi or any number ofstandardized or non standardized radio frequency communication links.

There are many possible implementations for the human interfaceapparatus that support both visual and audio content for humaninterpretation. Some examples are: laptop computer palmtop computer,PDA, smart phone, or a thick or thin client video audio custom device.For purposes of descriptive clarity, the preferred embodiment will use awireless Bluetooth™ data link, and the human interface apparatus is alaptop computer.

Therefore, the preferred embodiment the integrated golf club, inaddition to the previous described electronics, also has data formattingfor wireless transport using Bluetooth™ transceiver protocols. The data,once transferred over the wireless link to the laptop computer, areprocessed and formatted into visual and or audio content with aproprietary software program specific for this invention. Examples ofuser selectable information formats and content could be:

-   -   1. a dialog window showing a graphical representation of the        clubface using a color force representation of the maximum force        gradient achieved conveying the area of impact of the ball and        along the side the graphic could show text describing key        metrics such as maximum force achieved, radial acceleration of        club at impact (related to club head velocity) and total energy        transferred to the ball;    -   2. a motion video of the time varying nature of the forces on        the clubface;    -   3. a three dimensional graphic showing force vectors on club        head from ball;    -   4. an audio response which verbally speaks to the golfer telling        him/her the desired metrics;    -   5. a video showing time varying acceleration vectors of the golf        club head during the swing and through impact; or    -   6. numerous other combinations of audio and visual user defined.

Still yet another advantage of the present invention provides for theintegrated golf club that can be battery operated, or have batteriesthat are rechargeable or replaceable.

BRIEF DESCRIPTION OF DRAWINGS

The above and other features of the present invention will become moreapparent upon reading the following detailed description in conjunctionwith the accompanying drawings, in which:

FIG. 1 is a perspective view of the present invention integrated golfclub head (golf club shaft not shown) with impact pressure force sensorsembedded in the clubface and a three dimensional g-force accelerationsensor inside the club head;

FIG. 2 is a perspective view of the present invention as shown in FIG. 1except showing dashed line A and without depiction of the sensors;

FIG. 2A is a cross sectional view of the club head of the presentinvention of FIG. 2 taken along line A showing club face structure withtwo metal layers and therebetween the impact pressure force sensors andembedding material;

FIG. 2B is a cross sectional view of the club head of the presentinvention of FIG. 2 taken along line A showing the clubface structurewith two metal layers therebetween the impact pressure force sensors andembedding material, and including placement of a three dimensionalg-force acceleration sensor;

FIG. 3 is a partially exploded cross sectional view of the club headface construction of the present invention showing two metal layers bothrigidly attached the club head housing;

FIG. 4 is a perspective view of the present invention illustrating athree dimensional g-force sensor located at the center of gravity of theclub head;

FIG. 5 is a block diagram of sensors and electronic processing functionsinside of integrated golf club of the present invention;

FIG. 6 is a block diagram detailing the processing steps for the triggermechanism and commencement of data capture during the club swing andsubsequent data transmission of the present invention;

FIG. 7, depicting sub-FIGS. 7a -7 d, details a golfer swing time lapseshowing associated data capture and processing steps of the presentinvention;

FIG. 8 details the present invention integrated golf club transmittingcaptured swing and impact data to a remote user interface wirelessly toa laptop computer;

FIG. 9 is a block diagram of a user definable format portion of the dataprocessing and human interface software running on a laptop computer ofthe present invention;

FIG. 10 is a block diagram of the present invention detailing userselectable content metrics that are available for the audio and textformat options in the software;

FIG. 11 a block diagram of the present invention detailing userselectable content metrics that are available for the still graphics andmotion graphics format options in the software;

FIG. 12 is a partially exploded cross sectional view of an alternativeembodiment of the club head face construction of the present inventionshowing two metal layers of which only the inner metal layer is rigidlyattached to the club head housing;

FIG. 13 is a partially exploded cross sectional view of an alternativeembodiment of the club head face construction of the present inventionshowing a single metal layer and a hard material other than metalembedding the pressure force sensors that is the outer surface of theclub head face;

FIG. 14 is a perspective view of an alternative embodiment of thepresent invention depicting a golf club head embodiment using two threedimensional g-force sensors;

FIG. 15 details an alternative embodiment of the present inventionshowing the integrated golf club communicating results directly from theclub to the golfer using audio means;

FIG. 16 depicts a perspective view of a further alternative embodimentof the present invention that does not utilize pressure force sensors,and;

FIG. 17 depicts another alternative embodiment where the electronicmodule is combined with a display module and mounted on a golf clubshaft, with one or more single or multi-dimensional acceleration g-forcesensor or sensors mounted in the club head.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present invention comprises an integrated golf club that measuresdirectly and stores time varying forces during the golf club swing inthe time span from before the golf club head and ball impact, to a pointin time after club head and ball separation. Two categories of physicalparameters are being measured. in real time simultaneously withdifferent mechanisms that both convert directly to time varying forcevectors. The force vectors from each measurement mechanism areinterdependent in time and fixed spatial relation to one another as theclub head transitions through all of the different dynamic forces duringa golf swing, ball impact and after impact.

As shown in FIG. 1, the golf club head 10, has; a three dimensionalg-force acceleration sensor 20 mounted in the center of the club head.In one of many embodiments for this invention, the sensor can be placedat the center of gravity of the club head 40 (FIG. 4) for simplificationof metric calculations. However, the sensor does not have to be locatedat the center of gravity and all metrics defined are still achievable.The club head 10, also has an array of impact pressure force sensors 30embedded in the golf club head face 11. The hosel 8 on club head 10holds the shaft (not shown) of the club.

As shown in FIGS. 2, 2A and 2B the club head 10 and a club head crosssection 12 show the construction of the clubface 11 having two metallayers, the outer metal layer 13 and the inner metal layer 14. Thepressure force sensors 30 are imbedded in a non-metallic, non-electricalconducting medium of optimum physical properties 15 between the twometal layers as part of the clubface 11. The no-˜conducting medium 15 isa hard epoxy or similar material monolith structure with the pressuresensors 30 and their electrical connections embedded within it. Someexamples of possible materials include UV curable epoxies such as UVCure 60-7105™ or medium to hard composition of Vantico™ or one of thecompositions of Araldite™. The monolith structure can be created withexact pressure sensor placement and orientation with known injectionmolding technologies. An example of this process would be to make aninjection mold that creates half of the monolith structure and has halfpockets for a precise fit for each of the sensors and electricalconnection ribbon. The sensors with electrical connections are thenplaced in the preformed pockets of the initial half monolith. Theinitial half monolith with sensors is then placed in a second injectionmold which completes the entire monolith. The sensors 30 are attached toa flex circuit ribbon 17 a that will extend out from the monolithstructure, through a small pass through opening in the inner layer 14,that connects to the electronics assembly 18 in the club head cavity.

The non-conducting monolith material 15 with embedded pressure sensors30 can be pressure fit between the outer layer 13 and the inner layer14. The outer layer 13 and the inner layer 14 can be connected to theclub head housing 16 with conventional club head construction techniquesutilizing weld seam. Some techniques might include Aluminum MIG (MetalInert Gas) welding for aluminum to aluminum connection and brazing foraluminum to titanium connections. The clubface layers 13 and 14 can betitanium or comparable metal or alloy and the club head housingcomponents can be an aluminum alloy.

As seen in FIG. 2B, the mounting of the three dimensional accelerationforce sensor 20 will be attached to a small printed circuit board 29that holds the three dimensional sensor 20 or combination of one or twodimensional sensors 20 to give three dimensional measurementcapabilities. The small printed circuit board 29 will be attached with adurable adhesive to a metal or non-metallic rigid protrusion 19 attachedto the club housing either by adhesive, weld, fastener, or other wellknown connection, means, and extending to the spatial location that ispredefined for the sensor. The printed circuit board 29 is electricallyconnected with electronics assembly 18 with a flex ribbon 170. Thesurface areas 19 a of the protrusion 19 on which the sensor's printedcircuit board is mounted has a defined orientation within the club headto align the acceleration measurement axis with the pre-definedreference axis of the club head.

As shown in FIG. 3, which is the preferred embodiment of the presentinvention, the inner metal layer 14 is more rigid than the outerclubface layer B. Both the outer layer 13 and the inner layer 14 arerigidly attached to the club housing 16 through the aforementionedwelding process. In this configuration, the pressure exerted andresulting deformation on the clubface outer layer 13 by the golfclubface 11 and ball create a time varying pressure profile on thenon-metallic medium monolith 15. The individual pressure sensors 30 eachgenerate an output voltage proportional to the pressure experienced bythat sensor. The pressure sensors 30 in the preferred embodiment arepiezoelectric elements of the same surface area and thickness, thereforegenerating identical pressure force versus voltage profiles. In the casewhere the clubface inner 14 and outer 13 metal layers are both rigidlyconnected to the club head shell housing 16, the deformation of themonolith 15 will be less near the edge 28 of the clubface. This meansthat less pressure will be measured for the same impact force by sensorscloser to the edge of the club. These variations will be a constant withrespect to the fixed geometric shape of the club head and can becalibrated out in the digital signal process with fixed calibrationcoefficients programmed into the processing. Calibration could also bedone during production on a per club basis.

FIG. 4 shows an embodiment with only one three dimensional g-forcesensor 20 mounted at the center of gravity 40 of the club head 10. Thisconfiguration, in association with data from the pressure force sensorarray, can calculate all of the metrics listed earlier. However, sincethere is only a single point to measure club head rotation around thecenter of gravity and it is at the center of gravity, the radialacceleration vector sum is small and a very high resolution of thesignal measurement is required. A preferred method of maintainingaccuracy and lowering the measurement resolution requirement is to usemore than one three dimensional g-force sensors offset from the centerof gravity as seen in FIG. 14.

As shown in FIG. 5, the two sensor categories, both three dimensionalg-force sensor or sensors 200 and the pressure force sensors 100 areconnected to electronics that capture the time varying electricalsignals of all of the sensors simultaneously. The electrical signals mayor may not use signal conditioning 300 before they are input to thesimultaneous sample and hold function 401. The simultaneous sample andhold function 401 samples an sensor inputs and at a single point in timethen holds the value of each independent sensor for a short period oftime. During this short duration in time, the analog to digitalconversion function 402 takes each sample value and converts it to adigital representation. All of the digital samples for each sensor areassociated with that single sample time of acquisition in “the applysequencing group tag and the reference” function 403 and are then movedinto digital memory 404. The sampling rate of the simultaneous sampleand hold function 401 is at, or faster than, the “Nyquist rate”determined by the highest pertinent frequency component of all of thetime varying analog sensor inputs. After all data has been loaded intomemory storage 404 from a given golfer's swing, additional swing datacan be captured and stored or the data is further processed andformatted 405 for transfer to a user interface function. All of thefunctions listed are coordinated by a controller function 406, which maybe integrated together with other functions 400 such as a sophisticatedPIC (Periphery Interface Control) module with DSP (Digital SignalProcessing) functionality such as Motorola's HC11, HC12 and HC16 microcontroller families and MicroChip's dsPIC30 and dsPIC33 families. In apreferred embodiment, the signal is processed and formatted 405 to beapplied to a wireless transceiver 500, where it is transferred to aremote user interface such as a laptop computer. All of the functions inFIG. 5 that require electrical power to function are supplied by abattery power supply 600 that is detachable from the integrated golfclub or rechargeable if it is implemented as a permanent component ofthe golf club.

As shown in FIG. 6, the controller organizes and controls the electricalprocessing of the signals based on triggers. When the club is turned on,the controller is monitoring the g-force sensor 20 or sensors for apredefined level of acceleration force 701. Once the predefined triggerlevel is met, the controller knows that a golf swing has started 702.The controller then brings out of sleep mode or turns on the circuitryrequired for all sampling, analog to digital conversion, timing andprocessing to memory functions for a defined period of time 703. Thisdefined period of time can be either a preprogrammed duration of time ora acquisition circuitry stop function initiated by other trigger levelsindicating the swing is substantially past the point in time of clubhead and ball impact, at which time the data acquisition stops 704. Atthis point the golfer can take more swings and have data stored in theclub head memory in which case the controller goes back to step 701 orthe controller further processes the data for transfer to a humaninterface function. In the preferred embodiment, this processing ispreparation for wireless transmission 705. Next, the controller executesthe wireless transmission to an external user interface apparatus, whichincludes transmission reception confirmation or if any data wascorrupted during initial transmission, retransmission of those datablocks 706. Once all data has been confirmed as received, the controllerresets all electronics in preparation for monitoring the g-force sensorsfor the next trigger 707.

Another option (not shown in FIG. 6) utilizes a manual switch that thegolfer physically tums on before initiating his swing and turns offafter completion of the swing. The switch initiates fun data acquisitionallowing the golfer to track acceleration dynamics of his entire swingincluding backswing and follow through.

FIG. 7 shows the processing steps described in FIG. 6 in conjunctionwith a golfer's swing. In FIG. 7a , the golfer is starting his swing andthe club movement and acceleration parameters are minimal at this point801. In FIG. 7b , the club head acceleration parameters hit the definedtrigger level and definitively indicate a swing is in progress at whichpoint all of signal capture and processing circuitry is turned on 802.In FIG. 7 c, the club makes contact 803 with the ball 803 a and all ofthe data collection circuitry is still recording all sensor information.In FIG. 7d , the club stops recording sensor data at point 804.

FIG. 8 shows a preferred embodiment of the invention. The golf clubtransmits the measured data from the golf club to a remote userinterface wirelessly 1001. The user human interface apparatus could be asmart phone, PDA, computer or custom wireless enabled thin or thickclient device. In the preferred embodiment˜the human interface apparatusis a laptop computer 1002. The laptop computer 1002 may have wirelessabilities already built in for wireless communication such as WiFi,Bluetooth™, Zigbee™ or others. If the laptop doesn't have integratedwireless hardware and protocols to communicate wirelessly, a USBwireless adapter and associated software may be used. The laptop 1002will have software 1100 running on it that is associated specificallywith processing the time varying synchronized data from the golf clubinto golf performance metrics for human interpretation in many differentuser selectable and definable formats.

FIG. 9 shows the software 1100 capabilities and the structure of theprogram. The software 1100 will give great flexibility to the golfer asto how information is conveyed 1120 and what metrics information isconveyed 1130.

As seen in FIG. 10 the me tries information 1130 that can be conveyed isbroken into four categories: (1) audio; (2) text; (3) still graphics;and (4) motion graphics which are time dilation sequenced graphics thatwould play as a time expanded video of various time varying metrics.Since the content that can be displayed in text is the same content thatcan be conveyed through audio which are scalar values, these two groupsof user selectable metrics can be combined 1131. The available contentfor the still graphic options 1132 and the motion graphics options 1133are more complex, therefore they each have their own unique selectablemetrics lists.

As shown in FIG. 11, the still graphic options 1132 and the motiongraphics options 1133 are more complex in the sense they both conveythree dimensional spatial metrics. However, the motion graphics 1133adds the fourth dimension of time to create a powerful understanding forthe golfer as to the dynamic nature of the metrics being presented.

FIG. 12 shows an alternative embodiment of the club head faceconstruction where the outer metal layer 13 of the club face 11 is notrigidly connected to the club head housing 16 and the inner layer 14 isrigidly connected the golf club head housing 16. The outer layer 13 isconnected to the non-metallic, significantly hard monolith 15 that hasthe sensor array 30 embedded within it. The outer layer 13 is attachedto the monolith material 15 with a strong durable adhesive. The monolithmaterial 15 is also attached to the inner layer 14 with a durableadhesive. The inner layer 14 is rigidly connected. to the club housing16 with a welded seam as heretofore disclosed.

FIG. 13 shows yet another embodiment of the club head face constructionwhere there is only an inner metal layer 14 and the outer surface of theclubface 11 is the embedding material 15 that encapsulates the array ofpressure force sensors 30. The embedding material 15 in this case is anon-conducting, very hard, durable non brittle material. Many materialsexist that could be used and some example material families could bepolycarbonates or very hard polymers. In this embodiment, the monolithmaterial 15 is also attached to the inner layer 14 with a durableadhesive, while the inner layer 14 is rigidly connected to the clubhousing 16 with a welded seam.

As shown in FIG. 14, a preferred embodiment has two, three dimensionalg-force sensors. An inner three dimensional g-force sensor 20 a mountedon the axial center of gravity 41 of the club head 10 near where theclub shaft connects, and an outer three dimensional g-force sensor 20 bthat is also mounted on the axial center of gravity 41 but on the otherside of the club head and at an equal distance from the center ofgravity 40 as that of the inner three dimensional g-force sensors 20 a.In addition, each sensor's axial domain will have one axis normal to theclubface and one axis coincident with the axial center of gravity 41.There can be any reasonable number of the three dimensional g-forcesensors 20 mounted in the golf club head 10 and that are not alignedwith the center of gravity or associated axis. However, as long as thesensors' positions and orientations are known in relation to the massdistribution of the club head, the needed calculations can be made. Byutilizing relationships to the center of gravity, the calculations aresimplified.

FIG. 15 shows one embodiment after the point in time when theelectronics stop collecting data 804. The collected data is processed inthe club head into key metrics that are useful to the golfer. Thesemetrics are then communicated to the golfer directly from the golf club.The metrics content can be conveyed in several forms, one of which is anaudible signal or sequence of audible signals from the club 901 such asa synthesized voice stating metrics. Other forms of communication fromthe golf club to the golfer could include signals that are vibratedthrough the club handle for privacy or temperature variations in theclub handle.

FIG. 16 shows an alternative embodiment that only encompasses one ormore g-force sensors 20, without any pressure force sensors 30 included.The golf club invention of this design offers a subset of metrics thatinclude:

-   -   1. Total energy transferred from club to ball;    -   2. Time varying three dimensional motional acceleration and        associated force vectors on club head before, during and after        club head face and ball impact;    -   3. Radial acceleration forces on the club for an estimation of        club head velocity;    -   4. Three dimensional deceleration force vectors of club head        during the club/ball impact;

Although specific embodiments of the invention have been disclosed,those having ordinary skill in the art will understand that changes canbe made to the specific embodiments without departing from the spiritand scope of the invention. The scope of the invention is not to berestricted, therefore, to the specific embodiments. Furthermore, it isintended that the appended claims cover any and all such applications,modifications, and embodiments within the scope of the presentinvention.

FIG. 17 shows yet still another alternative embodiment that is a golfclub 1200 with golf club head 1201, a golf club shaft 1202 and a grip1203 on the shaft 1202. In this embodiment, the golf club head 1201 canhave either a one dimensional or two dimensional acceleration g-forcesensor 1204. The one dimensional g-force sensor or sensors 1204 isconnected through wire 1205 to electronic circuitry and display module1206 connected to the club shaft 1202 near the golf club hand grip 1203.The human interface display screen 1206 a can be of graphics or textformat such as OSRAM's Pivtiva™ OLED models or Varitronic™ LCD models,respectively. The electronic circuitry and display module 1206 collectsignals from the g-force sensor or sensors 1204, processes: thosesignals, converts the signals to metrics and displays the metricsregarding the swing of the golf club on the display 1206 a.

The electronic module may also have the ability to receive data from thegolfer, such as arm length, which can be used for calculations of golfclub head velocity. In this form of the invention, the arm length datumis input into the electronic circuitry and display module 1206 by asmart wheel 1206 b, or some such other similar means.

I claim:
 1. A golf swing measurement and analysis system comprising:first and second impact sensors that detect impact of a golf club head;and sampling circuitry that is coupled to the first and second sensors,wherein the sampling circuitry samples the first and second sensorssimultaneously at a single point in time.
 2. The golf swing measurementand analysis system of claim 1, wherein the sampling circuitry furtherholds for a period of time a first value sampled from the first sensorand a second value sampled from the second sensor at the single point intime, wherein analog to digital conversion of the first and secondvalues occurs during the period of time.
 3. The golf swing measurementand analysis system of claim 2, further including a processor thatapplies a sequencing group tag and time reference to both the first andsecond values and stores the sequencing group tag, time reference, andfirst and second values in a digital memory.
 4. The golf swingmeasurement and analysis system of claim 1, wherein the samplingcircuitry samples at a sample rate at least as fast as a Nyquist ratedetermined by a highest frequency component of all of a plurality ofanalog sensors connected to the sampling circuitry, the plurality ofanalog sensors including the first and second sensors.
 5. The golf swingmeasurement and analysis system of claim 1, further including first andsecond accelerometers, wherein the first and second accelerometers arealso simultaneously sampled by the sampling circuitry at the point intime.
 6. A golf swing analysis system comprising: a clubface; first andsecond impact sensors embedded in the club face; and sampling circuitrythat samples the first and second impact sensors, wherein the firstimpact pressure sensor is at a first location further from a centerpoint of the club face than a second location of a second impactpressure sensor, wherein the first and second impact sensors arecalibrated differently based on the first and second locations.
 7. Thegolf swing analysis system of claim 6, wherein the first and secondsensors are piezoelectric elements of a same surface area and thickness.8. The golf swing analysis system of claim 6, wherein the clubface hasan edge that is connected to a club head shell housing such that theclubface deforms less near the edge than at the center point.
 9. Thegolf swing analysis system of claim 6, wherein the calibration isaccomplished with fixed calibration coefficients that are set within aprocessing circuitry of the system.
 10. The golf swing analysis systemof claim 6, wherein the first and second impact sensors are sampledsimultaneously by the sampling circuitry.